The Last of Us season 2 was a disaster, (worse than the game even); So here's some tips for season 3 (if not cancelled obviously):
[SPOILERS]

1. Abby ACTUALLY kills Ellie!
After the last scene when Abby shoots Ellie, then black out => she dies from bleeding while having flashbacks and regrets towards Joel

2. From now on, it's a REVENGE story with Dina as main character:
She lost Jessie (father of her baby), she lost Joel, father figure, and good friend, which she couldn't defend when captured by Abby's group (survival's guilt etc...), and she lost Ellie of course.

3. Flashbacks about Dina: before Jacksonville, and later with Jessie, Joel and others
 (a tiny bit of younger Ellie in Jackson is ok, let's not exclude her completely, and see how she went from a nice child, to an unbearable teenadult ...)

4. More zombies and less Joel's flashbacks:
We don't need to see Pedro Pascal anymore, enough of him already, too much hype for a destroyed character. 
Use his salary's budget to make more interesting and "believable" zombie situations, and bring back the atmosphere of the game please!!!

PS: Dina's story can go in parallel to Abby's story with the WLF, for a contrasted (even longer) season

Side note: Neil could even pretend, to have had those ideas already, the reason why he made Ellie a detestable character, so we'd be glad for her death ... I'm fine with it!